using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.InteropServices;

using System.Reflection;

using System.Diagnostics;

using System.Windows.Forms;

namespace PublicHook

{

    /// <summary>

    ///存放回调函数的委托

    /// </summary>

    public delegate int HOOKPROC(int nCode, IntPtr wParam, IntPtr lParam);

    public enum HookType

    {

        WH_KEYBOARD = ,        //私有键盘钩子

        WH_EKYBOARD_LL = ,    //全局键盘钩子

        WH_MOUSE = ,           //私有鼠标钩子

        WH_MOUSE_LL =         //全局鼠标钩子

    }

    public abstract class hook

    {

        //设置钩子

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern int SetWindowsHookEx(HookType idHook, HOOKPROC lpfn, IntPtr hInstance, int threadId);

        //取下钩子

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern bool UnhookWindowsHookEx(int idHook);

        //获取当前线程一个唯一的线程标识符

        [DllImport("kernel32")]

        public static extern int GetCurrentThreadId();

        //传递消息给下一个钩子

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);

        //获取一个应用程序或动态链接库的模块句柄

        [DllImport("kernel32.dll")]

        public static extern IntPtr GetModuleHandle(string name);

        /// <summary>

        /// 钩子处理委托

        /// </summary>

        public HOOKPROC proc;

        /// <summary>

        /// 钩子类型

        /// </summary>

        public HookType type;

        /// <summary>

        /// 钩子的句柄

        /// </summary>

        public int hHook = ;

        public hook(HOOKPROC proc, HookType type)

        {

            this.proc = proc;

            this.type = type;

        }

        //设置回调函数

        public void SetProc(HOOKPROC proc)

        {

            this.proc = proc;

        }

        public abstract int SetWindowsHookEx();

        public virtual void UnhookWindowsHookEx()

        {

            bool retKeyboard = true;

            //当前钩子句柄不为空，卸载钩子

            if (hHook != )

            {

                retKeyboard = UnhookWindowsHookEx(hHook);

                hHook = ;

            }

            if (!retKeyboard)

                throw new Exception("UnhookWindowsHookEx failed.");

        }

    }

    public class PublicKBHook : hook

    {

        public PublicKBHook(HOOKPROC proc)

            : base(proc, HookType.WH_EKYBOARD_LL)

        { }

        public override int SetWindowsHookEx()

        {

            if (hHook == )

                hHook = SetWindowsHookEx(this.type, this.proc,

                    GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName), );

            return hHook;

        }

        //Hook结构

        [StructLayout(LayoutKind.Sequential)]

        public class HookStruct

        {

            public int vkCode;

            public int scanCode;

            public int flags;

            public int time;

            public int dwExtraInfo;

        }

        /// <summary>

        ///回调函数,屏蔽除了回车和tab之外的所有键盘消息

        /// </summary>

        public int MyKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam)

        {

            if ( nCode >=  )

            {

                HookStruct hookStruct = (HookStruct)Marshal.PtrToStructure((IntPtr)lParam, typeof(HookStruct));

                //如果按下了回车，则将消息传给下一个钩子

                if ((Keys)hookStruct.vkCode == Keys.Enter ||

                    (Keys)hookStruct.vkCode == Keys.Tab)

                    return CallNextHookEx(hHook, nCode, wParam, lParam);

                //后门

                if ((Keys)hookStruct.vkCode == Keys.F1)

                    UnhookWindowsHookEx( hHook );

            }

            return ;

        }

    }

    public class PrivateKBHook : hook

    {

        public PrivateKBHook(HOOKPROC proc)

            : base(proc, HookType.WH_KEYBOARD)

        { }

        public override int SetWindowsHookEx()

        {

            if (hHook == )

                hHook = SetWindowsHookEx(this.type, this.proc, IntPtr.Zero, GetCurrentThreadId());

            return hHook;

        }

    }

    public class PublicMouseHook : hook

    {

        public PublicMouseHook(HOOKPROC proc)

            : base(proc, HookType.WH_MOUSE_LL)

        { }

        public override int SetWindowsHookEx()

        {

            if (hHook == )

                hHook = SetWindowsHookEx(this.type, this.proc,

                    GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName), );

            return hHook;

        }

        /// <summary>

        /// 屏蔽除了鼠标移动之外的鼠标消息

        /// </summary>

        public int MyMouseProc(int nCode, IntPtr wParam, IntPtr lParam)

        {

            //当wParam = 0x0200 时，进行鼠标移动操作

            //直接将消息传递给下一个钩子

            if (wParam == (IntPtr)0x0200)

                return CallNextHookEx(hHook, nCode, wParam, lParam);

            return ;

        }

    }

    public class PrivateMouseHook : hook

    {

        public PrivateMouseHook(HOOKPROC proc)

            : base(proc, HookType.WH_MOUSE)

        { }

        public override int SetWindowsHookEx()

        {

            if (hHook == )

                hHook = SetWindowsHookEx(this.type, this.proc, IntPtr.Zero, GetCurrentThreadId());

            return hHook;

        }

    }

}

            //钩子句柄

            int hKBHook = , hMouseHook = ;

            //设置全局键盘钩子

            PublicKBHook myKBHook = new PublicKBHook(null);

            myKBHook.SetProc(myKBHook.MyKeyboardProc);

            hKBHook = myKBHook.SetWindowsHookEx();      

//撤销钩子

                myKBHook.UnhookWindowsHookEx();